package org.python.pydev.shared_core.partitioner;

import org.eclipse.core.runtime.Assert;

/**
 * Standard implementation of <code>IToken</code>.
 */
public class Token implements IToken {

    /** Internal token type: Undefined */
    private static final int T_UNDEFINED = 0;
    /** Internal token type: EOF */
    private static final int T_EOF = 1;
    /** Internal token type: Whitespace */
    private static final int T_WHITESPACE = 2;
    /** Internal token type: Others */
    private static final int T_OTHER = 3;

    /**
     * Standard token: Undefined.
     */
    public static final IToken UNDEFINED = new Token(T_UNDEFINED);
    /**
     * Standard token: End Of File.
     */
    public static final IToken EOF = new Token(T_EOF);
    /**
     * Standard token: Whitespace.
     */
    public static final IToken WHITESPACE = new Token(T_WHITESPACE);

    /**
     * Standard token: Neither {@link #UNDEFINED}, {@link #WHITESPACE}, nor {@link #EOF}.
     * @deprecated will be removed
     */
    @Deprecated
    public static final IToken OTHER = new Token(T_OTHER);

    /** The type of this token */
    private int fType;
    /** The data associated with this token */
    private Object fData;

    /**
     * Creates a new token according to the given specification which does not
     * have any data attached to it.
     *
     * @param type the type of the token
     * @since 2.0
     */
    private Token(int type) {
        fType = type;
        fData = null;
    }

    /**
     * Creates a new token which represents neither undefined, whitespace, nor EOF.
     * The newly created token has the given data attached to it.
     *
     * @param data the data attached to the newly created token
     */
    public Token(Object data) {
        fType = T_OTHER;
        fData = data;
    }

    /**
     * Re-initializes the data of this token. The token may not represent
     * undefined, whitespace, or EOF.
     *
     * @param data to be attached to the token
     * @since 2.0
     */
    public void setData(Object data) {
        Assert.isTrue(isOther());
        fData = data;
    }

    @Override
    public Object getData() {
        return fData;
    }

    @Override
    public boolean isOther() {
        return (fType == T_OTHER);
    }

    @Override
    public boolean isEOF() {
        return (fType == T_EOF);
    }

    @Override
    public boolean isWhitespace() {
        return (fType == T_WHITESPACE);
    }

    @Override
    public boolean isUndefined() {
        return (fType == T_UNDEFINED);
    }
}
